living genus
Sphenodontia Sphenodontia wedge tooth arose in the Mesozoic era and includes only one living genus, Tuatara, comprising two species that are found in New Zealand Figure 29.26 . Tuataras measure up to 80 centimeters and weigh about 1 kilogram. Although quite lizard-like in gross appearance, several unique features of the skull and jaws clearly define them and distinguish the group from the squamates.